Acid plating bath and method for the electrolytic deposition of satin nickel deposits

ABSTRACT

The plating bath for the deposition of satin nickel deposits according to the present invention contains at least one quarternary ammonium compound and at least one polyether, the at least one polyether having at least one strongly hydrophobic side chain. As compared to prior art plating baths, this acid plating bath has the advantage that it enables a long period of operation or heating and cooling cycles or filtration cycles, makes it possible to perform the filtration needed for continually operating the bath without using active carbon, requires a lower concentration of nickel than prior art baths to produce the satin gloss finish and has a reduced sensitivity to wetting agents that have been dragged in.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. National Stage under 35 U.S.C. 371 ofInternational Application PCT/EP03/05134 filed on May 15, 2003 whichclaims priority to German patent application DE 102 22 962.7 filed onMay 23, 2002.

This application is the U.S. National Stage under 35 U.S.C. 371 ofInternational Application PCT/EP03/05134 filed on May 15, 2003 whichclaims priority to German patent application DE 102 22 962.7 filed onMay 23, 2002.

BACKGROUND OF THE INVENTION

The invention relates to an acid plating bath and to a method for theelectrolytic deposition of satin nickel deposits. Electrolytes forobtaining matte nickel deposits, by contrast, do not form part of thisinvention.

In nickel electroplating, one generally tries to achieve a bright, leveldeposit. It has also soon been found out that silk matte deposits havean aesthetic appearance while preventing disturbing blinding effects.Combined with semi-bright nickel and with a chromium layer, such typelayers provide the same protection from corrosion as a bright nickellayer. These satin nickel layers are widely used in the automotiveindustry, in precision mechanics, in the sanitary industry andeventually even in the furniture industry.

Hereto before, the satin effect could be produced using various methods.At first, the satin effect was obtained using mechanical methods withthe bottom layer being matted by sandblasting. Later, insolublesubstances of a certain fineness such as glass, French chalk, bariumsulfate, graphite, kaolin or similar substances were added to the nickelelectrolyte. Whereas the first method involved a considerable expenseand did not fit in the electroplating process, the satin effect obtainedusing the insoluble substances was rougher than silk matte and had anirregular surface.

Organic substances that are difficult to dissolve, comprising in partstabilizing wetting agents did not show any lasting success:

DE-OS 1 621 085 discloses an acid nickel plating bath to provide satinnickel deposits that, in addition to primary brighteners, contains aconcentration of such type substituted or unsubstituted adducts ofethylene oxide or propylene oxide or ethylene oxide/propylene oxidewhich, at a temperature of 40-75° C., form a fine emulsion in theelectrolyte bath with said concentration ranging from 5 to 100 mg/l.

Further, DE 25 22 130 B1 describes an acid, aqueous nickel plating bath,nickel/cobalt plating bath or nickel/iron plating bath for depositingsilk matte layers that contains, in addition to the primary and/orsecondary brighteners, emulsified liquid polysiloxane polyoxyalkyleneblock copolymers.

Moreover, in Patent Abstract of Japan, the document JP 56152988Adiscloses a nickel bath for depositing satin coatings that contains, inaddition to saccharine as a brightener and topolyoxyethylene-polyoxypropylene block copolymers, wetting agentsselected from the group of the alkylaryl sulfonates and of esters ofsulfosuccinic acid. In this case as well it was established that a satinnickel layer can only be obtained for a short period of time after thebath has been prepared. After that, the coatings obtained are rough andunsightly.

DE 21 34 457 C2 furthermore discloses an aqueous electroplating bath fordepositing bright nickel or nickel/cobalt layers. According to someexamples, an ester of sulfosuccinic acid is, among others, added tobaths already containing saccharine as a secondary auxiliary brightener.These baths are not used to produce satin layers.

A method that has gained much more acceptance makes use of adducts ofpolyalkylene oxide, mostly adducts of ethylene oxide/propylene oxide,with water or aliphatic alcohols, that dissolve completely in the coldnickel electrolyte but are insoluble at an operating temperature of50-60° C. (DE-OS 1 621 087). It is known that, upon exceeding the cloudpoint temperature, the non ionogenic surface active agents precipitateby getting rid of their hydrate shell. These precipitating dropsselectively disturb the deposition of nickel without being substantiallyincorporated into the nickel. The disadvantage of this method is thehigh expense of energy for heating and cooling as well as for pumping.The maximum volume of the bath is also restricted since, as it reachesabout 8,000 liter, the expense for heating, cooling and pumpingincreases dramatically. Moreover, agglomerates, which produce blackpits, often form after a short period of time.

In view of the shortcomings described, a method is gaining increasingacceptance in which quaternary ammonium compounds are utilized in thebath. DE 23 27 881 A1 describes a method of producing matte nickeldeposits or nickel/cobalt deposits by which the matt deposits areobtained by incorporating foreign substances. The foreign substances areachieved by combining cationic active or amphoteric substances withorganic anions. Possible cationic active or amphoteric substances arequaternary ammonium compounds, imidazoline derivatives, esters ofalkanolamines and surfactants based on amino carboxylic acid. Togetherwith the anionic primary brighteners contained in the nickelelectrolyte, the cationic active substances form ion pairs that aredifficult to dissolve and that produce a satin effect by disturbing thenickel deposition process. Unfortunately, this method also hasdisadvantages:

Within approximately 3-5 hours the precipitating, difficult to dissolveion pair crystallites increase in size and produce an increasinglycoarse nickel surface or even clearly visible coarse single nickelcrystals (“diamonds”) that are very detrimental to the appearance of thenickel surface. Therefore, the production must be disrupted after 8hours at the latest to completely filter and clean the electrolyte usingfiltering means such as a cellulose filter, kieselguhr or even activatedcarbon. This disruption in production is very disturbing and verycostly, more specifically if an automatic machine is being used.Moreover, a film that may be wiped off often forms after chromiumplating for 10 minutes and longer (“silver layer”).

Some attempts have been made to overcome this shortcoming. One solutionconsisted for example in combining the two methods and in addingorganic, aromatic sulfinic acids to the bath intended to produce satinnickel deposits. Such a bath composition is described in DE 37 36 171A1. In this case, no optically uniform deposits are obtained withoutcooling and heating.

The use of a concentration of highly effective non ionogenic wettingagents (polyethylene glycol monomethyl ether) so small that the bathlacks any visible cloudiness is not successful either. DE 195 40 011 A1indicates another method for the electrolytic deposition of nickeldeposits with no blinding effect that makes use of a nickel bathcontaining inter alia primary brighteners, organic sulfinic acids andwetting agents. The bath further contains a concentration of substitutedand/or unsubstituted adducts of ethylene oxide or of propylene oxide orof ethylene oxide/propylene oxide so small that the bath lacks anyvisible cloudiness at the operating temperature of the bath. The use ofthe indicated concentration of non ionogenic wetting agents is notsuccessful because their efficiency decreases very soon and theappearance of the deposit quickly changes.

All of the methods described can only be operated for a few hours. Animprovement was achieved by using esters of sulfosuccinic acid togetherwith ammonium compounds (DE 100 25 552 C1). The high amount of nickelions in excess of 105 g/l required and the sensitivity to foreignwetting agents (that have been dragged in) are disadvantageous, though.Furthermore, the bath, which needs cleaning, can only be successfullycleaned with active carbon, which is quite inconvenient to handle sincethe filter can only be used once and the filter residue has to bedisposed of after each cleaning. On the other side, problems ariseduring chromium plating because of the formation of a film that may bewiped away (“silver layer”).

SUMMARY OF THE INVENTION

It is therefore the object of the present invention to provide a bathand a method for electrolytic deposition of nickel with a satin glossfinish that do not give rise to the afore mentioned problems and thatmore specifically enable a long period of operation or heating andcooling or filtration cycles, make it possible to perform the filtrationneeded for continually operating the bath without using active carbon,require a lower concentration of nickel than prior art baths to producethe satin gloss finish and have a reduced sensitivity of the bath towetting agents that have been dragged in.

The solution to this problem is achieved by the acid plating bath forthe electrolytic deposition of satin nickel deposits and by the methodfor the electrolytic deposition of a satin nickel deposit describedherein.

Before the present invention of acid plating nickel deposits with asatin gloss finish is disclosed and described, it is to be understoodthat this invention is not limited to the particular process steps andmaterials disclosed herein as such process steps and materials may varysomewhat. It is also to be understood that the terminology used hereinis used for the purpose of describing particular embodiments only and isnot intended to be limiting since the scope of the present inventionwill be limited only by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

It has been found that a stable satin effect is obtained during nickeldeposition if at least one polyether, each having at least one stronglyhydrophobic side chain, is added to the electrolyte intended to producesatin nickel deposits and containing at least one quaternary ammoniumcompound that acts as a cationic active wetting agent. For this purpose,a substrate to be coated is brought into contact with the inventiveelectrolyte plating bath and a flow of electric current is set betweenthe substrate and one anode.

The nickel electrolyte preferably contains at least one anionic primarybrightener and may contain a concentration of nickel of already lessthan 100 g/liter, for example of at least 70 g/liter.

In the case in accordance with the invention, the efficiency of thepolyethers with strongly hydrophobic side chains corresponds to that ofa typical wetting agent, the strongly hydrophobic side chain selectivelyinterfering with the deposition of nickel from the bath so that thenickel deposited has a satin gloss finish. The compounds of theinvention are soluble in the electrolyte so that a clear solution can beformed. These compounds are preferably used below their cloud pointtemperature. In this event, they do not form an emulsion. They may beutilized in a concentration that may in any event be greater than 5mg/l. Through the addition of the polyethers with strongly hydrophobicside chains it is possible to operate the electrolyte plainly withpartial current filtration, without using active carbon. It has beenrecognized that perfluorated alkyl chains or organic silicone chains,respectively siloxane chains in particular, exhibit this outstandingeffect. Ordinary long-chained alkyl ethoxylates or alkyl propoxylates donot exhibit this effect.

Accordingly, the advantages of the presence of polyethers with stronglyhydrophobic side chains in the electrolyte intended to produce satinnickel deposits are:

1. Preparing a stable dispersion even in electrolytes containing up to100 g/l of nickel ions. A nickel ion content of 70 g/liter willgenerally be sufficient.

2. The dispersion can be removed from the electrolyte through simplefiltration. The electrolyte can be operated plainly with partial currentfiltration, without using active carbon.

3. Thanks to the improved efficiency of the polyethers with stronglyhydrophobic side chains, a film that may be wiped away (“silver layer”)is prevented from forming after chromium plating.

4. There are no interferences with usual wetting agents of the classesalkyl sulfates, alkyl ether sulfates or alkylaryl sulfonates which arebeing utilized to prevent the formation of pits in baths for producingbright or semi-bright deposits.

5. In adding the polyethers with strongly hydrophobic side chains, thesatin effect is increased, which is particularly appreciated by userslooking for a plain satin effect. With the known nickel electrolytes, asatin effect can only be achieved by adding large quantities ofquaternary ammonium compounds. This in turn reduces the life of theelectrolyte for producing satin nickel deposits.

The at least one polyether with strongly hydrophobic side chainspreferably has the following general chemical formula (I):

wherein

-   -   R¹ and R^(1′) are independently hydrogen or methyl and can be        selected independently in each [(CH₂CHR¹O)]_(a)—CHR^(1′)—CH₃        unit of the polyether,    -   R³ is hydrogen or a linear chain or branched chain C₁- to        C₁₈-alkyl,    -   a is an integer from 0 to 500,    -   Z is a grouping selected from the group comprising a single        bond, CH₂, O, NR⁴, SO₂, S, NR⁴SO₂, COO, CO and NR⁴CO, wherein R⁴        is hydrogen or a linear chain or branched chain C₁- to C₁₈-alkyl        group,    -   R² is a moiety selected from the group comprising

wherein

-   -   the chains of the groups having the formulae (II), (III)        and (IV) can be either linear or branched;    -   X is a single bond or O;    -   n and m are integers from 0 to 12, wherein n+m is at least 1;    -   o is either 0 or 1;    -   p is an integer from 2 to 12;    -   q is an integer from 0 to 6;    -   R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰ and R¹¹ are selected independently and        are each a moiety selected from the group comprising hydrogen, a        linear chain or branched chain C₁- to C₁₈-alkyl and substituted        or unsubstituted phenyl; and        instead of a hydrogen atom the hydrophobic side chain —Z—R² is        bound to a carbon atom of the unit (CH₂CHR¹O) in the polyether        or to a carbon atom of the end group —CHR^(1′)CH₃ in the        polyether.

For a, the unit [(CH₂CHR¹O)]_(a) has a range preferably greater thanzero. a more preferably has a range of at least 1, and more specificallyranges from 1 to 500.

The units (CH₂—CHR¹—O) in the general formula (I) can be selectedindependently in any unit within the molecule so that these polyalkyleneglycol groups can be present in the form of a block polymer or of acopolymer. If the polyalkylene glycol group is present in the form of ablock polymer, a polypropylene unit can be arranged between apolyethylene unit and the R³O-group or a polyethylene unit between apolypropylene unit and the R³O-group.

Several hydrophobic side chains —Z—R² can be bound to the polyalkyleneglycol group. The hydrophobic side chains —Z—R² can thereby be bound toany carbon atoms of the polyalkylene glycol group with a respective oneof the hydrogen atoms in the general formula (I) being replaced by ahydrophobic side chain —Z—R². Preferably, one hydrophobic side chain atmost is bound to each unit (CH₂—CHR¹—O) of the polyalkylene glycolgroup. According to a particular embodiment, it is altogether alsopossible to have but one hydrophobic side chain bound to thepolyalkylene glycol group. Further instead of a hydrogen atom thehydrophobic side chain —Z—R² can also be bound to a carbon atom of theend group CHR^(1′)—CH₃ of the polyether grouping.

R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰ and R¹¹ preferably are hydrogen or alinear or branched C₁- to C₄-alkyl and most preferably methyl.

In a preferred embodiment of the invention Z is O, if R² is given by oneof the general formulae (III) and (IV) and if X is a single bond in thecase of the general formula (III).

In another preferred embodiment Z is CH₂ if R² is given by the generalformula (II).

The polyethers with strongly hydrophobic side chains listed in Table 1have proved particularly efficient.

The concentration of the polyethers with the strongly hydrophobic sidechains in the nickel electrolyte is very low and can range from 0.005 to5 g/l, preferably from 0.005 to 0.5 g/l, more specifically be of 0.1g/l. More specifically preferred is a concentration of the polyetherswith strong hydrophobic side chains in the range of from 20 to 100 mg/land most preferred a concentration of 50 mg/l if a long lasting effectis wanted. It has to be taken into consideration that commercializedproducts are hardly ever 100 percent pure but generally contain waterand sometimes even low alcohols acting as a solubilizer. Theconcentration values given herein above are related to a 100 percentpure product.

The electrolyte for the deposition of nickel deposits with the addedpolyether having strongly hydrophobic side chains generally consists ofa nickel salt solution that may additionally contain a weak acid as abuffering agent.

In practice, a Watts bath is used, which has the following composition:

280-550 g/l nickel sulfate (NiSO₄•7 H₂O)  30-150 g/l nickel chloride(NiCl₂•6 H₂O)  30-50 g/l boric acid (H₃BO₃)

The pH of the bath can range from 3 to 5.5, preferably from 3.8 to 4.4.To increase the cathodic current density, the temperature may range upto 75° C. It preferably ranges from 50° C. to 60° C.

The electrolytes intended to produce satin nickel deposits contain from10-50 g/l chloride and yield the best results using the polyethers withstrongly hydrophobic side chains. Nickel chloride can also be replacedin part or in whole with sodium chloride. The chloride in theelectrolyte can be replaced in part or in whole with stoichiometricallyequivalent amounts of bromide. In part, the nickel salts can also bereplaced with cobalt salts. When using the high performance electrolytesindicated and adjusting the temperature to 55° C., the current densityamounts to up to 10 A/dm². Usually, the current density ranges from 3 to6 A/dm². The exposure time in the electrolyte for producing satin nickeldeposits preferably amounts to 1 to 20 minutes, most preferred is a timeof 6 to 12 minutes.

The polyethers with strongly hydrophobic side chains can be added aloneto the electrolyte. However, optimum results are only obtained byconcurrently using primary brighteners. In additionally using these, anexcellent deposit with satin gloss finish can be achieved over theentire current density range needed for practical operation, saiddeposit with satin gloss finish appearing to be optically uniform duringan operation of the electrolyte of at least 15 hours and lacking anyhaze that can be wiped away if chromium plating is conducted for a longtime.

By primary brighteners unsaturated, mostly aromatic sulfonic acids,sulfonamides or sulfimides or the salts thereof are meant. The bestknown compounds are for example m-benzene disulfonic acid or benzoicacid sulfimide (saccharine) as well as the salts thereof. Known primarybrighteners, which in most cases are used in the form of the sodium orpotassium salts thereof, are indicated in Table 2. It is also possibleto use several primary brighteners simultaneously.

The primary brighteners according to Table 2 are added to theelectrolyte in an amount of about 5 mg/l, more specifically of 50 mg/l,up to 10 g/l, preferably of from 0.5 to 2 g/l. If these compounds aloneare added to the electroplating bath they produce a bright deposit in acertain current density range. Therefore, the exclusive use thereof hasno practical significance. The desired satin effect is only obtained byfurther adding, in addition to said compounds, quaternary ammoniumcompounds.

The quaternary ammonium compounds are cationic active wetting agentshaving the general formula (V)

wherein

-   -   R^(a), R^(b), R^(c) and R^(d) may be the same or different and        be a linear or branched, possibly unsaturated C₁- to C₁₈-alkyl        chain; mixtures of natural components such as tall, cocos,        myristyl and lauryl groups may be utilized, and R^(b) and R^(c)        may be hydrogen;    -   R^(d) most preferably is a C₁- to C₄-alkyl group or possibly an        alkyl substituted aromatic group such as for example a benzyl        group;    -   X⁻ preferably is an anion, e.g., chloride, bromide, formate or        sulfate.

Examples of these quaternary compounds are listed in Table 3.

The quaternary ammonium compounds are used in a concentration of about0.1 mg/l, more specifically of about 5 mg/l, up to 100 mg/l. Currentwetting agents used to prevent the formation of pits in the deposit neednot be added to the electrolyte intended to produce a satin nickeldeposit; most of these compounds disturb the deposition of nickel.

The work piece to be electroplated is slowly moved during deposition.Additional air injection is seldom used. Circulation pumps and possiblyan overflow are often needed. They promote uniform deposition of satinnickel layers. During the deposition process, the plating bath ispreferably continuously or discontinuously pumped and/or filtered.

A combination of the polyethers having strongly hydrophobic side chainswith quaternary ammonium compounds having at least one ester ofsulfosuccinic acid also yields aesthetic satin type nickel deposits.These electrolytes are stable for a long time. In the present case, theesters of sulfosuccinic acid of preference have the general formula(VI):

wherein

-   -   R^(e) and R^(f) may be the same or different and may be a linear        or branched or cyclic C₁- to C₁₈-alkyl chain, which is possibly        unsaturated or interrupted by ether groups, wherein one of the        two groups R^(e) and R^(f) also may be a hydrogen ion (acid        group) or an alkali ion, an ammonium ion or an alkaline earth        ion;    -   A may be a hydrogen ion (acid group) or an alkali ion, an        ammonium ion or an alkaline earth ion.

The esters of sulfosuccinic acids listed in Table 4 have provedefficient.

The following examples will serve to explain the invention in closerdetail:

EXAMPLE 1.0

At first 0.015 g/l of the quaternary ammonium compound No. 7 (Table 3)was added to an electrolyte having the following composition:

290 g/l nickel sulfate (NiSO₄•7 H₂O)  40 g/l nickel chloride (NiCl₂•6H₂O)  40 g/l boric acid (H₃BO₃)  3 g/l primary brightener No. 7 (Table2) in the form of a sodium salt.

The electrolyte was tested in a 100 liter tank at 55° C. with the workpieces being moved. A scratched, bent copper sheet of 7 cm×20 cm waselectroplated for 17 minutes at 2.5 A/dm². The resulting deposit had anirregular, quite weak satin gloss finish over the entire sheet as thenickel content was too low.

EXAMPLE 1.1

0.015 g/l of the polyether compound No. 2 (Table 1) was additionallyadded to the electrolyte of Example 1.0 (with the same nickel content).

The test was performed as described in Example 1.0. The deposit obtainedhad a uniform, intense satin gloss finish over the entire sheet.

Result of the Examples 1.0 and 1.1: without the polyethers having ahydrophobic side chain being used and with the nickel content chosen,the deposit obtained had a quite weak, irregular satin gloss finish,whereas, with the polyethers with hydrophobic side chain being used, thedeposit obtained had an intense, uniform satin gloss finish with anoutstanding optical appearance.

EXAMPLE 2.0

At first 0.015 g/l of the quaternary ammonium compound No. 6 (Table 3)was added to an electrolyte having the following composition:

430 g/l nickel sulfate (NiSO₄•7 H₂O)  40 g/l nickel chloride (NiCl₂•6H₂O)  40 g/l boric acid (H₃BO₃)  3 g/l primary brightener No. 7 (Table2) in the form of a sodium salt.

The electrolyte was tested in a 10 liter tank at 55° C. with the workpieces being moved. A scratched, bent copper sheet of 7 cm×10 cm waselectroplated for 15 minutes at 2.5 A/dm². The resulting deposit had aslightly irregular, weak satin gloss finish over the entire sheet.Neither defects nor black pits could be detected. Every hour a sheet wastested and then compared with those tested previously. After four hours,the sheets already showed a coarser, unsightly deposit. After fivehours, the test had to be discontinued as the quality was too bad(irregular to matte).

EXAMPLE 2.1

At first 0.015 g/l of the quaternary ammonium compound No. 6 (Table 3)and in addition thereto 0.02 g/l of the polyether compound No. 5(Table 1) were added to the electrolyte of Example 1.0.

The test was performed as described in Example 1.0. The deposit obtainedhad a uniform, strong satin gloss finish over the entire sheet. Neitherdefects nor black pits could be detected. Every hour a sheet was testedand then compared with those tested previously. After 15 hours the testwas discontinued as the deposits still continued to show the same goodquality.

Result of the Examples 2.0 and 2.1: without the polyether compound, thelife time of the electrolyte was of 4-5 hours only. By additionallyusing the polyether compounds, the life time of the electrolyte could beprolonged to more than 15 hours. On the other hand, with the polyethercompounds being used, the appearance was much more attractive. Thedeposit obtained had a very uniform, strong satin gloss finish over theentire sheet.

It is to be understood that various modifications and substitutions bytechnically means may be applied to what has been described by way ofthe examples and of the drawings hereinabove, without departing from thescope of the invention as defined by the appended claims.

TABLE 1 Polyethers with strongly hydrophobic side chains operatingconcentration No. [mg/l 1 polyethylene glycol octa dimethyl siloxaneether 5-500 2 polyethylene glycol-polypropylene glycol-hexa 2-400dimethyl siloxane ether (copolymer or block polymer) 3 polyalkyleneglycol tetra silane ether 2-400 (copolymer or block polymer) 4polypropylene glycol octa dimethyl silane ether 5-600 5 perfluoroctylsulfonamidopolyethoxylate 5-500 6 perfluorhexylsulfonamidopolypropoxylate 1-300 7 perfluorbutylsulfonamidopolyalkoxylate  5-1000 (copolymer or block polymer withethylene and propylene oxide) 8 polyethylene glycol perfluoroctane acidester 5-500 9 polypropylene glycol perfluor hexyl ether 5-600 10perfluoroctyl sulfone-(N-ethyl)- 4-400 amidopolyethoxylate 11 methylpolyalkylene glycol polymethyl siloxane 5-500 ether 12 polyethyleneglycol-ω-tridecafluoroctane ether 10-800 

TABLE 2 Primary brighteners No. 1 m-benzene disulfonic acid 2 vinylsulfonic acid 3 allyl sulfonic acid 4 propyne sulfonic acid 5 p-toluenesulfonic acid 6 p-toluene sulfonamide 7 benzoic acid sulfimide 81,3,6-naphthalene trisulfonic acid 9 benzoyl benzene sulfonamide

TABLE 3 Quaternary ammonium compounds No. 1 dioctyl dimethyl ammoniumchloride 2 didecyl dimethyl ammonium chloride 3 didodecyl dimethylammonium bromide 4 dodecyl dimethyl benzyl ammonium chloride 5tetradecyl dimethyl benzyl ammonium chloride 6 hexadecyl dimethyl benzylammonium chloride 7 cocosyl dimethyl benzyl ammonium chloride 8 stearyldimethyl benzyl ammonium chloride 9 oleyl dimethyl benzyl ammoniumchloride 10 dilauryl dimethyl ammonium bromide

TABLE 4 sulfosuccinic acid ester No. 1 sulfosuccinic acid dibutyl ester2 sulfosuccinic acid diisobutyl ester and all the homologues of thiscompound 3 sulfosuccinic acid dioctyl ester 4 sulfosuccinicacid-bis-(1,3-dimethyl butyl)-ester 5 sulfosuccinic acid dihexyl ester 6sulfosuccinic acid-bis-(2-ethyl hexyl ester)-ester 7 sulfosuccinic aciddiisooctyl ester and all the homologues of this compound 8 sulfosuccinicacid diisopropyl ester 9 sulfosuccinic acid dipentyl ester 10sulfosuccinic acid dicyclo hexyl ester 11 sulfosuccinic acid monododecylester

1. An acid plating bath for the electrolytic deposition of satin nickeldeposits containing a nickel electrolyte, at least one quaternaryammonium compound and at least one polyether, the at least one polyetherhaving at least one strongly hydrophobic side chain, wherein the atleast one polyether has the following general chemical formula (I):

wherein R¹ and R^(1′) are independently hydrogen or methyl and can beselected independently in each [(CH₂CHR¹O)]_(a)—CHR^(1′)—CH₃ unit; R³ ishydrogen or a linear chain or branched chain C₁- to C₁₈-alkyl; a is aninteger from 0 to 500; Z is a grouping selected from the groupconsisting of a single bond, CH₂, O, NR⁴, SO₂, S, NR⁴SO₂, COO, CO andNR⁴CO, wherein R⁴ is hydrogen or a linear chain or branched chain C₁- toC-₁₈-alkyl group; R² is a moiety selected from the group consisting of

and wherein the chains of the groups having the formulae (II) and (III)can be either linear or branched; X is a single bond or O: n and m areintegers from 0 to 12, wherein n+m is at least 1; o is either 0 or 1;R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰ and R¹¹ are selected independently and are eacha moiety selected from the group consisting of hydrogen, a linear chainor branched chain C₁- to C₁₈-alkyl and substituted or unsubstitutedphenyl; and instead of a hydrogen atom the hydrophobic side chain —Z—R²is bound to a carbon atom of the unit —CH₂—CHR¹—O— or to a carbon atomof the end group —CHR^(1′)—CH₃.
 2. The acid plating bath according toclaim 1, wherein Z is O if R² is given by the general formula (III) andif X is a single bond.
 3. The acid plating bath according to claim 1,wherein Z is CH₂ if R² is given by the general formula (II).
 4. The acidplating bath according to any one of claims 1 to 3, wherein the group—Z—R² is bound to a carbon atom of the end group CH₃ of the at least onepolyether instead of to a hydrogen atom.
 5. The acid plating bathaccording to any one of the preceding claims 1-3, wherein the at leastone polyether is selected from the compounds consisting of polyethyleneglycol octa dimethyl siloxane ether, polyethylene glycol-polypropyleneglycol-hexa dimethyl siloxane ether copolymer, polyethyleneglycol-polypropylene glycol-hexa dimethyl siloxane ether block polymer,polyalkylene glycol tetra silane ether copolymer, polyalkylene glycoltetra silane ether block polymer, polypropylene glycol octa dimethylsilane ether, and methyl polyalkylene glycol polymethyl siloxane ether.6. The acid plating bath according to any one of the preceding claims1-3, wherein the concentration of the at least one polyether ranges from0.005 to 0.5 g/l.
 7. The acid plating bath according to any one of thepreceding claims 1-3, wherein at least one primary brightener isadditionally included.
 8. The acid plating bath according to claim 7,wherein the concentration of the at least one primary brightener rangesfrom 0.005 to 10 g/l.
 9. The acid plating bath according to any one ofthe preceding claims 1-3, wherein the concentration of the at least onequaternary ammonium compound ranges from 0.000 1 to 0.1 g/l.
 10. Theacid plating bath according to any one of the preceding claims 1-3,wherein at least one sulfosuccinic acid ester is additionally included.11. The acid plating bath according to any one of the preceding claims1-3, wherein at least one cobalt ion source is additionally included.12. The acid plating bath according to claim 1, wherein the acid platingbath is an electroplating bath.
 13. A method for the electrolyticdeposition of a satin nickel deposit onto a substrate, comprising themethod steps: a) contacting the substrate with the acid plating bathaccording to any one of claims 1, 2, 3, and 12; and b) setting a currentflow between the substrate and an anode.
 14. The method according toclaim 13, wherein the plating bath is pumped and/or filteredcontinuously or discontinuously.